Air cylinder with pilot valve in head

ABSTRACT

A fluid control arrangement including a cylinder having a pair of spaced heads joined by a hollow body in which a piston is mounted for reciprocal movement. A valve unit is provided in a valve bore integrally formed within at least one of the heads of the cylinder. The valve unit includes a spring-biased reciprocable valve member having a valve operator integrally formed therewith and extending into the hollow body so as to be in actuatable relation with the piston. A pair of conduit openings extend into the valve bore, and, depending upon the positioning of the valve member in the bore due to the operation of the piston, communicate with or are blocked from each other.

United States Patent [72} Inventor Ignazio James Coniglio Chicago, Ill.

[2l] Appl. No. 880,468

[22] Filed Dec. 8, 1969 [45] Patented Jan. 19, 1971 [73] Assignee [54]AIR CYLINDER WITH PILOT VALVE IN HEAD f 5 Claims, 5 Drawing Figs. U [52]U.S. Cl 91/306, 137/6256, l37/624.14 [51] Int. Cl F011 25/06 [50] Fieldof Search 91;306;305/04001970; 137/(lnquired), 625.69

[56] References Cited UNITED STATES PATENTS 2,296,647 9/1942 McCormick91/306 3,162,093 12/1964 Zoller 91/306 3,352,324 11/1967 Strykerl37/625.69

Primary ExaminerPaul E. Maslousky Attorney-Olson, Trexler, Wolters &Bushnell ABSTRACT: A fluid control arrangement including a cylinderhaving a pair of spaced heads joined by a-hollow body in which a pistonis mounted for reciprocal movement. A valve unit is provided in a valvebore integrally formed within at least one of the heads of the cylinder.The valve unit includes a springbiased reciprocable valve member havinga valve operator integrally formed therewith and extending into thehollow body so as to be in actuatable relation with the piston. A pairof conduit openings extend into the valve bore, and, depending upon thepositioning of the valve member in the bore due to the operation of thepiston, communicate with or are blocked from each other.

AIR CYLINDER WITH PILOT VALVE IN HEAD This application is a continuationof application Ser. No; 750,998 filed July I8, 1968, now abandoned,which in turn was, also, a continuation of application Ser. No. 570,075,filed Aug. 3, 1966, now abandoned. y

This invention relates generally to pneumatic control circuitry and moreparticularly to pneumatic control circuitry which incorporates apneumatic or hydraulic cylinder jack and pneumatic pilot valve.

The movement of a pneumatically operated piston has heretofore beenemployed to actuate pneumatic pilot valve. However, in the prior artarrangements, the pilot valves have been mounted outside of the pistoncylinder to be actuated, for example, by a radial projection on theexposed piston rod. Such arrangements have proved costly to install andto maintain, have resulted in congested work areas around piston rods,and have presented reliability problems. 7

An important object of the present invention is therefore to provide apneumatic control arrangement which overcomes the foregoing limitationsof the prior art.

Another object of the invention is to provide a pneumatic control systemwherein one or more pilot valves are arranged to be actuated directly bythe pneumatically operated piston.

Still another object of the invention is to provide a pneumatic controlarrangement in which pilot valves are integrally incorporated in apneumatic cylinder, thereby eliminating bulky appendages.

These and other objects and features of the invention will become moreapparent from aconsideration of the following descriptions.

A pneumatic control arrangement in'accord with the invention includesacylinder having spaced heads and a hollow body connecting the heads.One of the heads of the cylinder is fashioned with a valve bore and withspaced pneumatic conduits opening into the bore. A reciprocable pistonissituated in the cylinder, and a valve unit is located in the headhaving the valve bore. The valve unit itself includes a valve operatorthat projects from the valve bore through an inner wall portion of thecorresponding head into actuatable relationship with the piston, and areciprocable valve member is arranged in the bore to move with the valveoperator (preferably being integral therewith), the valve member beingprovided with flow control passageway means for selectively connectingthe pneumatic conduits.

In order thatthe principles of the invention may be readily understood,two embodiments thereof, but to which the application is not to berestricted, are shown in the accompanying drawing wherein:

FIG. 1 is a perspective view of a pneumatic control arrangementconstructed in compliance with the invention, a portion of the pistonhousing being broken away to show internal details;

FIG. 2 is an enlarged, fragmentary view taken substantially along theline 2-2 of FIG. 1;

FIG. 3 is a further enlarged view taken substantially along the line 3-3of FIG. 2;

FIG. 4 is a view similar to the showing of FIG. 3 but illustrating amodified form of the invention, differing from the arrangement of FIGS.l-3 in details of the valve unit; and

FIG. 5 is a view taken substantially along the line 55 of FIG. 4. i

In the examples of the invention hereinafter set forth the termpneumatic" is exemplary; hydraulic mechanisms and circuits are alsocontemplated. Referring now in detail to the drawing, specifically toFIG. I, a pneumatic control arrangement indicated generally by thenumeral is seen to comprise a pneumatic cylinder I2 and pneumatic pilotvalves 14 and 16. The cylinder I2 includes a pair of spaced heads 18 and20 of blocklike construction which are connected by a hollow cylindricaltube or body 22 in defining a housing for a reciprocable piston 24. Thepiston 24 is secured on a piston rod 26 by means of a radiallyprojectingflange 28, which may be defined by a washer, and a nut 30which turns on a threaded inner end 32 of the piston rod 26. On itsexternal end, the piston rod 26 carries a threaded attachment site 34 orother means for coupling the piston rod to an element which it isdesired to drive. The introduction and exhaust of pressurized fluid formoving the piston 24 are achieved by pipes 36 and 38 which are threadedinto or otherwise suitably connected with the heads I8 and 20respectively. The pipes 36 and 38 are connected by passageways 40 intothe hollow body 22. Radially outwardly of the external wall of the body22, the heads 18 and 20 are held rigidly against the hollow cylindricalbody 22 by cylindrical rods 97.

In compliance with the features of the present invention, the pilotvalves 14 and 16 are incorporated directly in the as sociated heads 18and 20 to be integral therewith; and turning to a consideration of FIGS.2 and 3, valve unit 16 comprises a valve operator 44 integral with areciprocable valve member '46, a flow directing arrangement 48 and abiasing spring 50.

The valve operator 44 projects through a reduced diameter end portion 52of a valve bore 53, bore 53 being fashioned in head 20 and operator 44extending through an inner wall portion 54 of head 20 into actuatablerelationship with the piston 24. In addition to the valve bore 53, thehead 20 is fashioned with pneumatic conduits 56 and 58 which openradially into the bore 53. It will be'apparent from an inspection ofFIG. 3, that the pneumatic conduits 56 and 58 are spaced longitudinallyof the axis of bore 53. Conveniently, an inlet fltting 60 is mounted incommunication with conduit 58, and an outlet fitting 62 is secured incommunication with the conduit 56. An exhaust conduit 64 may also bearranged to open into the valve bore 53 at a different longitudinalposition than either the conduit 56 or the conduit 58.

Although various means may be employed to provide ap propriateconnection between the valve operator 44 and the reciprocable valvemember 46, it has proved convenient and preferable to form themintegrally. The valve member 46 is in the nature of a spool valve memberincluding a cylindrical portion 66 and a spaced follower portion 68connected thereto by a reduced diameter or necked-down region 70, region70 forming an annular flow control passageway for selectively connectingthe pneumatic conduits 56 and 58. The valve member 46 also blocks fluidcommunication between the pilot valve and the main cylinder, as will beapparent hereinafter. Advantageously, the valve member 46 is drilledwith a bore 72 that defines a retainer for one end of spring 50. Being acompression spring, spring 72 requires an opposing abutment, and thislatter function is supplied by a plug 74 which is turned into a threadedbore 76 that is formed coaxially with the valve bore 53. Means ofsealing cap 74 and head 20 to prevent fluid from escaping from valvebore 53 is pro vided.

Cooperating with the annular chamber or groove that is defined bynecked-down region 70, the flow directing arrangement 48 comprises asystem of alternating resilient sealing means 78, conveniently rubberO-rings, and respectively labeled from left to right as 78b, 78c and78d, and spacing means or'ring spacers 80. Each of the spacing means orring spacers 80 is formed with a generally U-shaped cross section withthe closed end thereof disposed generally radially inwardly. Inaddition, each of the spacers 80 is perforated with a series of arcuateports 82 in the floor or inner collar thereof. Thus, each of the spacersdefines a radially outwardly opening groove which is communicated in theradially inward direction by means of the ports 82. In order to directflow between the several conduits 56, 58 and 64, one of the spacers 80is aligned radially with each of these conduits, as is well shown inFIG. 3. Cooperatively, the axial extent or length of the necked-downregion 70 is arranged to span the radial distance between immediatelyadjacent spacers-80.

At one extremity of its travel, piston 24 will forcibly engage the valveoperator 44 to drive the same inwardly and against the compressionspring 50. As the valve operator 44 moves inwardly, the necked-downregion 70 moves from the position shown in FIG. 3 until its axial lengthspans the radial distance between the conduit 56 and the conduit 58. Afluid path will thus be formed permitting a pressurized fluid to flow,for example, from conduit 58 through the ports 82 in the spacer 80aligned therewith, into the annular chamber defined by the necked-downregion 70 and the resilient seal 78 and thence through the ports 82 inthe spacer 80 aligned with conduit 56 and ultimately into the latterconduit. In this position portion 66 of the valve member engagesresilient seal 780 which in turn engages bore 53, blocking flow ofpressurized fluid to conduit 64. Upon retreat of the piston 24, thevalve operator 44 will be released to the action of spring 50 and/or theforce exerted by pressurized air on theequivalent area of the.followerportion 68 and the valve member 46 will be returned to its normaloutward position shown in FIG. 3 where the necked-down region 70communicates conduit 56 with exhaust conduit 64 and where followerportion 68 engages resilient seal 78d which in turn engages bore 53,blocking flow of pressurized air from conduit 58 to conduits 56 and/or64. In these movements of the valve member 46, the several resilientseals 78b, 78c and 78d provide a sealing action against both the wallsof valve bore 53 and the radially outwardmost surfaces of valve member46, specifically portions 66 and 68 thereof. Cylindrical portion 66always engages seal 7812, thereby blocking fluid communication betweenthe pilot valve and the main cylinder. It should be recognized that themovements of piston 24 may thus be employed, through the resultantmanipulations of pneumatic valve 16, to control the actuation of someother device, such as for example a related pneumatic cylinder, valve,or other device, or it may be employed in a servomechanism sense toprovide information about the position of piston 24.

In accordance with a feature of the invention, the conduit 58 comprisesa pressure inlet conduit as has been described hereinabove; and infurther accord with the invention, the conduit 56 comprises a pressureoutlet conduit between the pressure inlet conduit 58 and the inner wallportion 54 of head 20. With the pressure inlets and outlets and theexhaust conduit positioned as shown, fluid pressure from the inletconduit 58 cooperates with the bias established by spring 50 inresisting pressurized fluid forces imposed on the valve operator 44 andthe valve member 46 from within the hollow body of the cylinder 12, thuspreventing movement of operator 44 from its outward position by thesepressurized fluid forces.

The valve unit 14 is constructed like the valve unit 16 and operates ina similar manner.

Positioning of the pilot valves 14 and 16 within the cylinder heads 18and 20 profoundly simplifies the installation of a pneumatic controlarrangement incorporating a pneumatic cylinder and one or more pneumaticvalves. The expensive and time-consuming job of designing and installingthe mounting facilities for the pneumatic valves is entirely eliminated,and the effort involved in locating a suitable place to mount apneumatic valve is completely avoided. Furthermore, there is no need forconcern over the possibility of trip points shifting due to wear ormishap, Because the entire operating mechanism of the pneumatic valve issafely housed within a cylinder head, the risk of contamination fromdirt, grit and chips is virtually eliminated. Moreover, there are nocomplicated actuating mechanisms to wear out or deform from fatigue; theactuating force is in exact axial alignment with the movement of thevalve operator; and finally, costly electrical wiring is not required.Hence, the chance of explosion or fire resulting from spark hazard isnonexistent.

In FIG. 1 the main cylinder conduits or pipes 36 and 38 are shownschematically as extending to an external master valve 92 receivinginlet pressure as indicated. The valve is capable of alternatelysupplying pneumatic pressure to the ends of the main cylinder, andventing to atmosphere the nonpressurized end. The pilot valve outlets 62also extend to the valve 92 for controlling the position thereof. Thisarrangement causes the piston 24 to reciprocate continuously. Althoughthis feature is believed to be novel, it is clearly to be understoodthat pneumatic connections other than through the valve 92 arecontemplated.

While a particular embodiment of the invention has been thus far shownand described, it will be appreciated that many modifications may bemade. Therefore, and in order to enhance the understanding of theinvention, a modified form thereof is shown in FIGS. 4 and 5. The formof the invention shown in FIGS. 4 and 5 is similar in some respects tothe cmbodiment of H65. l--3 inclusive. Accordingly, like numerals havebeen used to designate like parts with the suffix letter being employedto distinguish those elements associated with the embodiment of FIGS. 4and 5.

The valve arrangement 16a, shown in FIGS. 4 and 5, is particularlycharacterized by the use of a tubular sleeve 84 as a flow directingmeans and as a spacer for the resilient seals 78a, sleeve 84 being fixedin the valve bore 53a in stationary position. The sleeve 84 is speciallyprovided with a precise longitudinal bore 86 as exemplified by a lappedbore. cooperatively, the valve spool operator member 460 is fashionedwith similarly precise surfaces 88, typically lapped with the bore. Inaddition, the sleeve 84 is provided with radially opening, annular,axially spaced seal grooves 90 which receive the resilient seals 78a;and flow passage grooves 92 are alternated with the gasket grooves 90.Each of the flow passage grooves 90 includes means to effect flow fromthe central bore of sleeve 84 to the respective, flow passage groove 92,specifically a plurality of radial apertures 93. Furthermore, the sleeve84 includes awall formation 94 between each of the gasket grooves 90 andthe longitudinal bore 86. Desirably, an internal, annular groove 96communicates the apertures 93 in each flow control groove radiallyoutwardly of the cylinder of bore 86.

The resilient seals 78:: are confined compressibly between the wall ofbore 53a and the walls of the gasket grooves 90, the gasket groovesbeing arranged to permit slight freedom of movement of the sealing meansfor facility in assembling the pilot valve 161: in the head 20a. Thecooperating precisely machined surfaces 86 and 88 effectuate a seal atthe interface of the sleeve 84 and the outside circumference of thespool operator or valve member 46a. To preserve and promote the usefullife of these precise surfaces, they are suitably hardened inmanufacture.

Operation of the valve unit 16a is similar to that of the valves 14 and16. The spool operator configurations are identical. The spool lands98b, 98c, and 98d correspond to the inner sealing portions of theresilient seals 78b, 78c, and 78d.

The specific examples herein shown and described are to be considered asbeing primarily illustrative, Various changes in structure will, nodoubt, occur to those skilled in the art; and such changes are to beunderstood as forming a part of this invention insofar as they fallwithin the spirit and scope of the appended claims.

I claim:

1. A pneumatic control arrangement comprising: a housing includingspaced heads of blocklike construction having mutually perpendicularfaces and a hollow, cylindrically shaped body connecting said heads atfirst faces thereof, a reciprocable piston in said hollow body, each ofsaid heads having a threaded bore extending thereinto from a second faceopposite said first face thereof, with a complementarily threadedimperforate access plug extending into said threaded bore and closingthe same to provide an internal imperforate abutment surface, and avalve bore integrally formed in said head in coaxial relation andaccessible communication with said threaded bore and closed by the plugseated therein, with spaced openings each extending through certain onesof said remaining perpendicular faces at right angles to the planesthereof into said valve bore and each of said openings receiving thereina conduit for transporting air under pressure therethrough, a pilotvalve unit in each of said valve bores and including annular flowdirecting means in a position of confinement between one end of thevalve bore and an adjacent portion of the plug at the'opposite endthereof and a valve member reciprocable with said annular flow directingmeans, said valve member having integrally formed therewith a valveoperator projecting from said valve bore through a reduced diameter endportion thereof in an inner wall portion of said head into actuablerelation with said piston, said valve member being spool-shaped andincluding a cylindrical portion and a spaced follower portion toward theplugend of said valve bore and connected to said cylindrical portion bya reduced, necked-down portion forming an annular flow passageway forselectively connecting said conduit openings, said valve member having acentral boreat least through said follower portion and compressionspring means within said valve bore and said central bore, contactingsaid valve member at one end and said plug abutment surface at the otherend thereof, said spring normally biasing said valve member in aposition whereby saidvalve operator extends into said hollow body,certain ones of said conduit openings being normally blocked from eachotherwhereby'upon the actuation of said valve operator by the movementof said piston within said hollow body into engagement with the formersaid valve member is moved correspondingly within said annular flowdirecting means to position said necked'down portion into communicationwith said certain ones of said conduit openings, thereby to allow for aflow of fluid therebetween.

2. A pneumatic control arrangementasclaimed in claim 1, wherein saidannular flow directing means includes spacer means locating annularsealing rings insaid valve bore in predetermined spaced positionsrelative to said spaced openings and with an inner portion of the plugin proximate position ofconfinement relative to adjacent spacer meansportions.

3. A pneumatic control arrangement as claimed in claim 2, wherein theplug abutment surface is within an inwardly directed annular flangethereon with the inner edge thereof in proximate position of confinementrelative to adjacent Spacer means portions.

4. A pneumatic control arrangement as claimed in claim 1, wherein saidannular flow directing means includes spacer means locating annularsealing rings in said valve bore in predetermined spaced positionsrelative to said spaced openings, and wherein the plug abutment surfaceis within an inwardly directed annular flange thereon with adjacentspacer means portions within said flange in the position of confinement.

5. A fluid control arrangement as claimed in claim 1, wherein first oneof said conduit openings comprises an inlet and a second one of saidconduit openings comprises an outlet, and wherein said valve borefurther includes an exhaust opening extending thereinto and being spacedfrom said fluid conduit openings, said exhaust opening,through saidneckeddown portion of said valve member, communicating with said outletwhen said valve member is in the normal position, and being blocked fromsaid outlet when said valve member is actuated by said piston.

1. A pneumatic control arrangement comprising: a housing includingspaced heads of blocklike construction having mutually perpendicularfaces and a hollow, cylindrically shaped body connecting said heads atfirst faces thereof, a reciprocable piston in said hollow body, each ofsaid heads having a threaded bore extending thereinto from a second faceopposite said first face thereof, with a complementarily threadedimperforate access plug extending into said threaded bore and closingthe same to provide an internal imperforate abutment surface, and avalve bore integrally formed in said head in coaxial relation andaccessible communication with said threaded bore and closed by the plugseated therein, with spaced openings each extending through certain onesof said remaining perpendicular faces at right angles to the planesthereof into said valve bore and each of said openings receiving thereina conduit for transporting air under pressure therethrough, a pilotvalve unit in each of said valve bores and including annular flowdirecting means in a position of confinement between one end of thevalve bore and an adjacent portion of the plug at the opposite endthereof and a valve member reciprocable with said annular flow directingmeans, said valve member having integrally formed therewith a valveoperator projecting from said valve bore through a reduced diameter endportion thereof in an inner wall portion of said head into actuablerelation with said piston, said valve member being spool-shaped andincluding a cylindrical portion and a spaced follower portion toward theplug end of said valve bore and connected to said cylindrical portion bya reduced, neckeddown portion forming an annular flow passageway forselectively connecting said conduit openings, said valve member having acentral bore at least through said follower portion and compressionspring means within said valve bore and said central bore, contactingsaid valve member at one end and said plug abutment surface at the otherend thereof, said spring normally biasing said valve member in aposition whereby said valve operator extends into said hollow body,certain ones of said conduit openings being normally blocked from eachother whereby upon the actuation of said valve operator by the movementof said piston within said hollow body into engagement with the formersaid valve member is moved correspondingly within said annular flowdirecting means to position said necked-down portion into communicationwith said certain ones of said conduit openings, thereby to allow for aflow of fluid therebetween.
 2. A pneumatic control arrangement asclaimed in claim 1, wherein said annular flow directing means includesspacer means locating annular sealing rings in said valve bore inpredetermined spaced positions relative to said spaced openings and withan inner portion of the plug in proximate position of confinementrelative to adjacent spacer means portions.
 3. A pneumatic controlarrangement as claimed in claim 2, wherein the plug abutmenT surface iswithin an inwardly directed annular flange thereon with the inner edgethereof in proximate position of confinement relative to adjacent spacermeans portions.
 4. A pneumatic control arrangement as claimed in claim1, wherein said annular flow directing means includes spacer meanslocating annular sealing rings in said valve bore in predeterminedspaced positions relative to said spaced openings, and wherein the plugabutment surface is within an inwardly directed annular flange thereonwith adjacent spacer means portions within said flange in the positionof confinement.
 5. A fluid control arrangement as claimed in claim 1,wherein first one of said conduit openings comprises an inlet and asecond one of said conduit openings comprises an outlet, and whereinsaid valve bore further includes an exhaust opening extending thereintoand being spaced from said fluid conduit openings, said exhaust opening,through said necked-down portion of said valve member, communicatingwith said outlet when said valve member is in the normal position, andbeing blocked from said outlet when said valve member is actuated bysaid piston.